Field of the Inventions
The present inventions relate to a method, a system and a computer program product for obtaining data for manufacturing a dental component and a physical dental model.
Description of Related Art
A dental restoration, such as a dental bridge, a crown, an onlay, or an inlay, can be prefabricated before it is installed into a patient. The dental restoration may be manually fabricated, e.g., by a dental technician, or manufactured using a CAD/CAM (Computer Aided Design/Computed Aided Manufacturing) procedure. One such CAD/CAM procedure, which includes various products and procedures, is provided within the Procera® concept by Nobel Biocare®. The dental restoration may be built up by a dental component forming a framework, such as a ceramic coping, and a veneering layer. The veneering layer may be formed with porcelain. The CAD/CAM procedure may be used to only manufacture the dental component, or the entire dental restoration.
Irrespectively whether the dental restoration is finalized manually or by means of the CAD/CAM procedure, the following steps are normally carried out. First, providing a preparation by preparing one or several teeth to be restored; next, taking an impression of at least one of the upper jaw and the lower jaw of a patient, which includes the preparation; casting based on the impression to provide a study cast of at least a portion of the patients dental structure, the preparation, and soft tissue; then, manufacturing the dental component; and finally, fitting and/or adjusting the dental component using the plaster study cast and an articulator to provide the dental restoration. The fitting operation may comprise forming the veneering layer. If the CAD/CAM procedure is utilized to form the veneering layer, a manual fitting operation may comprise grinding the veneering layer to provide accurate occlusion.
To obtain the geometry of the surface of the dental structure, and possibly adjacent soft tissue, of the patient, the impression is taken to form a negative model. A bite index may also be taken to record the spatial relationship of the teeth in the upper jaw and the teeth of the lower jaw of the patient. For the impression-taking process, an impression tray may be used. When the impression material has set, plaster is poured into the impression, whereby the positive model of the dental structure and adjacent soft tissue is provided once the plaster has set.
If the CAD/CAM procedure is used, the plaster study cast can be sectioned, wherein the portion of the study cast containing the model of the preparation is removed from the other portion of the study cast. The model of the preparation can be scanned using a probe scanner or an optical scanner to provide a data record containing information of the geometrical shape of the surface thereof. The data record can be sent to a manufacturing facility for manufacturing of the dental component.
The model of the upper jaw and the model of the lower jaw can be mounted into an articulator to be used during the fitting operation. The bite index can be used to provide a spatial relationship between the models of the upper and lower jaws, which corresponds to the spatial relationship between the teeth of the upper and lower jaw of the patient. When the study cast has been properly mounted in the articulator using the bite index, the fitting operation can commence.
When the veneering layer is added to dental component, the study cast may be used to check the accuracy of the dental component and/or as a die for forming the veneering layer. The study cast may also be used for occlusion fitting and/or checking. During the fitting operation, the dental component is seated on the model of the preparation. The dental component is normally manufactured using a high precision manufacturing procedure. Hence, a close interrelationship between the inner surface of the dental component and the outer surface of the model of the preparation is provided, as the model of the preparation was scanned to generate the data record for the dental component. Accuracy is important in order to, i.e. avoid cracking of the dental restoration after final installation on the preparation.